Installations of this type are already known. The coating station is used to coat the wall of formed containers with a layer of material improving the gas fluid-tightness properties of the container. This layer is, for example, made by plasma deposition on the inside of the container.
The improvement of the fluid-tightness is used particularly for formed containers for small-sized bottles, for example less than 80 cl, which are intended to be filled with a carbonated beverage. In the absence of this fluid-tightness layer, it was actually found that the gas contained in the carbonated beverages had a tendency to escape through the walls of the container too quickly to allow it to be put on the retail market.
Such a problem is not faced for larger-capacity bottles. Actually, the ratio between the volume of the bottle and the area of the wall makes it possible to limit the evaporation of the gas for a sufficiently long time to guarantee the level of gas in the beverage for the customer.
The coating station is positioned in sequence in a production line, downstream from a blow-molding station and upstream from a filling station.
Installations equipped with the coating station are consequently suitable for producing only small-capacity containers. Now, the producers of bottles in the future want production installations that can produce bottles of various sizes. In doing this, large-capacity bottles or bottles that are intended to be filled with a non-carbonated beverage have no need to be coated with a fluid-tightness layer.
Furthermore, when the operation of the coating station must be halted, for example for maintenance reasons, the entire production of the installation is stopped. The downtime of the installation thus leads to a significant loss of production for the producer.